The purpose of this study is to use near infrared optical tomography to study infants on extracorporeal membrane oxygenation. These infants are at risk for brain injury due to their underlying illness and anticoagulation. Current brain imaging of infants is done immediately prior to initiating ECMO and then daily once on ECMO is limited to a head ultrasound to detect hemorrhage and stroke. The presence of severe brain injury would exclude the infant from ECMO and would necessitate the withdrawal of ECMO for those infants already on ECMO. Early brain injury may not be visible on ultrasound if structural changes (hemorrhage, infarction) have not yet developed. TOFA allows noninvasive imaging of cerebral structure and function, including oxygen utilization and cerebral blood flow, at the bedside for prolonged periods. Alterations in cerebral function that occur with early brain injury can, therefore, be visualized prior to the development of structural injury. Recognition of early brain injury by TOFA may allow more timely intervention with improved neurologic morbidity.